Ceiling plenum and air conditioning system



June 19, 1956 G. M. RAPP 2,751,198 CEILING PLENUM AND AIR CONDITIONING SYSTEM Filed Jan. 5, 1951 [HVEJYZ 0P Georgeffliapp CEILING PLENUM AND AR CONDITIONING SYSTEM George M. Rapp, Hamden, Conn, assignor to Houdaille Industries, Inc., Detroit, Mich, a corporation of Michigan Application January 5, 1951, Serial No. 204,604 1 Claim. (Cl. 257-124) The present invention relates to a ceiling plenum airconditioning system and more particularly to a prefabricated ceiling tile unit defining an interior plenum chamber and including a heat exchanger having a perforate backing plate defining a diffusion surface.

In order to obtain greater uniformity of heat distribution Within an enclosed habitable space, it has been proposed that heated or otherwise conditioned air be introduced into the space through perforate ceilings. The method of air-conditioning utilizing such a perforate ceiling includes the conditioning or heating of the air at a point remote from the enclosed space, the conveyance of this conditioned air to plenum chambers or spaces above the perforate ceiling, and then the passage or eifluence of the air to the space to be conditioned through the ceiling itself.

The present invention now provides an improved form of ceiling plenum air-conditioning system wherein the air is heated or otherwise conditioned as it is diifused through the perforate ceiling into the space to be heated. More particularly, the present invention includes a plate and tube-type heat exchanger having a backing plate which is in greater than semi-peripheral contact with a heat exchange fluid conduit, preferably in the form of a sinuous tube having straight reaches thereof secured to the plate by deformation of the plate into contact therewith. The passage of heat exchange fluid through the tube will serve to heat or cool the backing plate which then provides a heat radiating or air-conditioning surface. In the present invention, the surface is apertured and air from the plenum chamber is passed through the apertured backing plate for diffusion into the space to be conditioned.

In the formation of a ceiling air-conditioning system, the heat exchanger preferably forms an integral part of a relatively shallow ceiling tile unit including a perforate backing plate bearing the heat exchanger conduits and having integral upturned marginal flanges which define relatively shallow pans. Preferably, sound absorbent material, in the form of prefabricated filler blocks, are carried by the pans intermediate the depths thereof to define a plenum chamber lying between the sound absorbent blocks and the heat spaced rows with the spaces utilized for the introduction of air from a desired fresh air source, air passing through the passages between thewhich coincide at the walls fore described. The grooves 17 receive therein the 2,751,198 Patented June 19, 1956 2 disposed within the tile units, so that air-conditioning and sound absorption is obtained.

Of course, it will be appreciated that the present invention may also be utilized as an air cooling system during the summer months with a refrigerant or similar coolant being circulated through the heat exchange fluid conduits. In this manner, year-around utilization of the ceiling is possible for improved air conditioning under any adverse weather conditions.

It is, therefore, an important object of the present invention to provide an improved ceiling plenum air-conditioning system utilizing a perforate heat exchange plate as a diffusion medium.

Another important object of the present invention, is to provide a ceiling tile unit defining an interior plenum chamber for the reception of air from a source and hav ing a perforate heat exchange surface defining a diffusion medium for accommodating the passage of air from the plenum chamber into a space to be heated.

It is a further important object of the present invention to provide a ceiling tile unit in the form of a relatively shallow pan having a sound absorbent material disposed therein in spaced relation to the pan bottom to define a plenum chamber therebetween for the reception of air from a source and the pan bottom being perforated for accommodating the flow of air therethrough from the plenum chamber to a space to be conditioned.

Still another important object of the present invention is to provide a ceiling plenum air-conditioning system including a plurality of ceiling tile units each providing a plenum chamber communicating through a perforate heat exchange surface with a space to be conditioned, and airflow spaces between adjacent tile units and communicating with a source of fresh air and the plenum chambers for introducing air into the plenum chambers for later diffusion through the heat exchange surface into the space to be conditioned.

Other and further important objects of this invention will be apparent from the disclosures in the specification and .the accompanying drawings.

On the drawings:

Figure 1 is a fragmentary plan view of a ceiling plenum air-conditioning system of the present invention;

Figure 2 is a plan view of an individual tile unit of the present invention;

Figure 3 is a fragmentary, greatly enlarged sectional view taken along the plane IIIIII of Figure 1;

Figure 4 is a fragmentary sectional view taken along the plane IVIV of Figure l; and

Figure 5 is a schematic illustration of an air-conditioning system of the present invention illustrating the flow of air through the system.

As shown on the drawings:

In Figure 1, reference numeral 10 refers generally to a ceiling plenum air-conditioning system adapted to be secured to a ceiling sub-structure of an enclosed habitable space.

More particularly, the ceiling of Figure 1 is composed of a plurality of individual prefabricated composite tile units 11 as best illustrated in Figures 2-4, inclusive. Each tile unit 11 takes the form of a relatively shallow tray having a bottom wall 12 and upstanding marginal side flanges 13 extending along the longer longitudinal sides of the tray a dual function of and transverse upturned side flanges 14 extending along the shorter sides of the trays and slotted as at 15 (Figure 2). The bottom wall 12 of each tray 11 is perforated, as at 16, the perforations being of any desired shape and either being merely punched, as illustrated, or punched. and drawn (not shown), if desired.

The bottom walls 12 are also provided with grooves 17 14 with the slots 15 heretostraight portions: only: of. awsinuous length of heat exchanger tubing 18, joining portions, 19. of... the ubing.

length extending laterally beyond the edges of the bottom wall or plate 12, so that it is not necessary to provide a sinuous groove 17.. Those portionsof bottom plate. 12 adjacent the tube groove 17 are deformed inwardly so that the plate 12 is in greater than semi-peripheral contact with the'outer surface of :the tube 18 along the entire length of the tube contacting the plate, these plate deformations being indicated generally at 191a (Figure 3). It will be seen that the. slots 15 accommodate the extension of the joiningturns19 of the sinuous tube length 18 beyond the confines of the plate, and it will be seen. that there is no interference between the plate end flange '14 and the tubing. Similarly, it will be seen that the tube 18 and the plate groove 17 extend into. the interior of the tray so that a substantially smooth tray undersurface is defined by the lower wall 12.

Intermediate the depth of the tray, the longitudinal flanges 13 carry seating members 29 in the form of right-angle brackets welded, brazed, or otherwise secured to the inner surfaces. of the flanges and having an inturned upper leg 20a extending in spaced, substantially parallel relation to the bottom plate 12. The angle brackets 20 support a prefabricated, generally rectangular block 21 of sound absorbent material having its under surface 21a resting uponv the angle bracket legs 29a so as to extend in parallel spaced relation to the bottom plate- 12. The blocks 21 are preferably sealed about their vertical edges, as at 22, to each of the flanges BT14 of the tile units 11. In this manner, the space A between the under surface of the block 21 and the bottom plate 12 is sealed along its upper extremity.

Inasmuch as the space A is sealed from the atmosphere thereabove by the sealing material 22 enclosing the block 21, the only communication of this space with the atmosphere is through the plate 12, so that the space A thus defines a plenum chamber directly overlying the plate 12 and communicating with the space therebeneath through the perforations thereof. Ingress to the plenum chamber A is provided by means of a plurality of slots or apertures 23 formed in those portions of the flange 14 communicating with the space A. A control for the ingress of air into the space A is provided by a valving element 24 defined by those portions of the flange 14 severed to provide the slots 23. It will be seen that the slots 23 are defined by generally three-sided incisions formed in the flanges with the severed flange portion being deflectablc along its line of juncture with the flange. The degree of deflection of the portion 24 controls the amount of air introduced into the space A and thereby the amount of air which is provided for diffusion through the plate 12.

It will be seen from Figures 1, 4 and that a ceiling air-conditioning system is preferably formed by the assembly of a plurality of tile units of the present invention in longitudinally aligned, transversely spaced rows. More particularly, a plurality of units 11 are assembled to define one row of tile units, and a plurality of additional units 11 are assembled in spaced relation to the first group of units to define a second row. The space 25 lying between the rows of units defines a duct common to both rows of units, and this duet preferably communicates with a primary duct 26 which in. turn communicates with a source of air under'difierential pressure. The ducts 25 defined between adjacent rows of units 11 are provided by an imperforate dummy plate 27 having upturned lateralside flanges 28 which are so dimensionedastobe insertableinto the space between adjacent rows of units 11. The dummy plate '27, being imperforate, merely serves to confine air to the duct 25 and air from the duct is permitted ingress into the plenum chambers A ofthe units on each side thereof throughthe slots 23 and-the partially or completely-opened valving elements 24 therefor. In this manner, air from the ducts is introduced into the plenumchambers for escape therefrom through the perforate plates 12 which therefore serve as diflusion slat sv uniform y pread n i m t plenum c ambers across the entire surface area of the plates.

Further, the diffusion plate 12 serves as a heat exchange surface for conditioning the air by radiation and convection, the air being first conditioned while in the chamber A and being further conditioned upon passage through and intimate contact with the plate 12. The heat exchange properties of the plate 12 will be readily appre ciated by those skilled in the art, inasmuch as the plate is in extended, greater than semi-peripheral surface contact with the heat exchange tubes 18 which are adapted for connection to the source of heated or refrigerated heat exchange fluid, as desired.

The different sinuous tubes 18 of adjacent rows of tile units are interconnected as best illustrated in Figures 1 and 4, so that a constant flow of heat exchange fluid throughout the system is possible. More particularly, the terminal portions 18a of the. tubes 18 extend beyond the confines of the plates 12, and these portions 18a of adjacent tile units are connected by means of couplings 28 which accommodate fluid flow between the various. units.

It will be appreciated that the system of the present invention is capable of year-around use, depending. upon whether the heat exchange fluid. flowing through the conduits 18 is heated or refrigerated. If the fluid is. heated, the plate 12 acts as. a radiation surface and air. pasSlT g through the dififusion plate and also contained. within the plenum chamber A will be heated. On the. other hand, if the heat exchange fluid flowing through the tube 13 is a coolant, a cooling eltect is exerted upon air within the plenum chamber A and passing through the diffusion plate 12.

The sound absorbent properties of the block 21 also serve to dcaden sound within the space to which air is being supplied to the diffusion plate 12, and the block 21 serves to isolate the plenum chamber A, so that flow therethrough is effectively directed through the plate, 12. The absorbent block 21 may be of any desired sound. b orbent material, num r u exampl s of which are well nown n he a or xample, a low-density ement: r a e mixture. or c ramic mate avi ppr nri. t po osity o e t ct v sound a so pt o good us c ty. or ater apo and good thermal insulat n va ue may be employ d H we e it s m ter a t e ma r al his. ater a an kn n. a M oporite be ut ediiu ated h drou a -inn i icat which s u y s: l edip U. leteut No. 2 71 Where a m ter a ha n ater v p asx y urea. erties is utilized, the block 21 also serves to automatically dehumidity a r Pass n t rou h the P enum sham ng A. S51E55 an t o a ad anta i there obtus n ic taieccnd tie us ontro s ma he u i zsqin ci iu i i w h he app ratu of the pres nt invests?! o hat tru y iise i e sen Q ins at a ma be 9 tained.

In or o insta h i e units of t 9%??? invention p n a ubss lin sewe s i ti tE-{R E which h fl n 13 a 14 a stashed ma be u ilizes. a'is'wfi Rnb'wh in he a e e e flan e ant leer terminate in flush relation with the upper extrem ty of the acoustic block 21, so that the units may be attached to the ceiling by means of an adhesive secured to the block 21 as is well lgnown 1n the sound absorption art.

The advantages residing in applicants invention will be readily appreciated by those skilled in the art, particularl since applicant prov-ides means for condition ng air from a source as the air is passed through a plenum chamber and a diffusion surface. Thus, thcreis no heat loss or heat gain during passage of the air from its source to the diffusion plate, thus greatly increasing the air conditioning efliciency of the entire system. Furthendhe presentiinvention combines its airc0nditioning functions with sound absorption and automatic airdehumidifica tion. Further, the provision of prefabricated composite tile units makes possible the obtaining of these three functions by means of a single installation, while the uti1ization of standard size units makes possible the adaptation of the system to any type of existing or newly built subceiling structure.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

In a ceiling plenum air-conditioning system, a plurality of rows of conditioning units, each unit comprising: a rectangular sheet metal pan having upstanding side and end walls and having a perforate bottom Wall deformed to provide a plurality of grooves in spaced parallel relation to each other and to said side walls, a length of heat exchange tubing extending sinuously on said bottom wall and including straight portions in said grooves and curved connecting portions projecting beyond said end walls with each end of said length of tubing also projecting beyond an end wall of said pan, and a block of sound absorbent material supported in said pan in spaced relation above said bottom wall and extending continuously over the entire cross section of the pan between the upstanding side and end walls thereof, said block having vertical edge surfaces sealed to said upstanding side and end walls to define therewith a plenum chamber sealed along its upper extremity, said units being disposed in aligned side-by-side relation in said rows with the end walls of the units of each row in spaced relation to the end walls of the adjacent rows, a plurality of imperforate plates coplanar with said bottom walls of said units and extending between the end walls of the units of each row and the end walls of the units of the adjacent rows, means disposed above said plates for interconnecting the heat exchange tubing of the units, said plates cooperating with said end walls to define air ducts between the rows of conditioning units and space for said connecting portions of the lengths of tubing with said plates being removable from below to provide access to said tubing interconnecting means, and each of said end walls being apertured to provide communication between said air duct and the plenum chambers of the units.

References Cited in the file of this patent UNITED STATES PATENTS 1,086,898 Crane Feb. 10, 1914 1,664,171 Hicks Mar. 27, 1928 1,744,517 Barker Jan. 21, 1930 1,880,877 Dick Oct. 4, 1932 2,172,771 Norris Sept. 12, 1939 2,180,945 Morey Nov. 21, 1939 2,382,340 Smith Aug. 14, 1945 2,646,971 Raskin July 28, 1953 2,677,749 Raider May 4, 1954 

